Design a Stateful Banking System with Scheduled Payments and Account Merges

Company: Airbnb

Role: Software Engineer

Category: Software Engineering Fundamentals

Difficulty: medium

Interview Round: Online Assessment

Quick Answer: Design an in-memory banking system with accounts, transfers, spender rankings, scheduled payments, cancellation, and account merges. Specify deterministic payment processing before public operations and preserve balances, outgoing totals, histories, and pending-payment ownership through merges.